Multiple myeloma is a malignant hematological disease dominated by monoclonal plasma cells in the bone marrow. Major symptoms are related to the bones due to an increased bone resorption and a decreased bone formation leading to bone pain and increased risk of fractures. The normal osteoclasts are responsible for bone degradation through stimulation from the malignant plasma cells. Bisphosphonates have been shown to inhibit the osteoclast activity but may have serious side-effects due to renal toxicity and the optimal dose have not been established.

In a randomized double blinded design it is aim to compare the standard of monthly injections of 90 mg pamidronate with 30 mg.

The primary end-point is physical function estimated by EORTC QLQ-C30 questionnaire at 12 months after starting the treatment in newly diagnosed treatment demanding multiple myeloma. Secondary end-points are skeletal related events, cost-utility analysis, response, response duration and survival and quality of life with respect to fatigue and pain.

Patients with newly diagnosed treatment demanding multiple myeloma are after informed consent and approved inclusion criteria randomised by telephone call to Copenhagen Trial Unit (CTU) and information on the target dose is send to the distributor, Amgros, and the local pharmacy for preparation of the pamidronate solution. Infusion is given for 2½ hours.

Before starting treatment the patient has to fulfil the first EORTC QLQ-C30 questionnaire that is send to the quality of life secretariat in Oslo, Norway. Subsequent questionnaires are mailed directly to the patients every third month.

The infusions are continued for 3 years and may be extended further upon the patient's request.

Every third month the number of skeletal event, the response and complications are recorded.

Skeletal X-rays are performed 9 and 24 months after starting the treatment.

Inclusion Criteria:

• New diagnosed multiple myeloma with treatment demanding disease

Exclusion Criteria:

• Life-expectancy less than 3 months, another active malignant disease, treatment with bisphosphonates for more than 3 months within the last 6 months, patients with creatinine above 400 µmol/l 4 weeks after starting chemotherapy, patients who cannot cooperate for monthly infusions, patients who do not give their informed consent